Browsing by Subject "HYPOTHESIS"

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  • Mäkinen, Viivi; Liebkind, Karmela; Jasinskaja-Lahti, Inga; Renvik (Mähönen), Tuuli Anna (2019)
    Existing prejudice-reduction interventions in schools mainly target majority students and are mostly conducted by researchers, which limits their use for anti-discriminatory practices in culturally mixed schools. We tested a teacher-led intervention aiming at prejudice-reduction among both minority and majority adolescents through vicarious contact. The effects of indirect vicarious contact rest on observed ingroup role models of intergroup contact who have positive attitudes towards the outgroup, and vice versa. However, the specific impact of vicarious contact exerted by outgroup role models in comparison with ingroup role models has never been studied in interventions conducted in naturalistic school settings. To fill these gaps, a field experiment was conducted among secondary school students in Finland (N-majority = 437; N-minority = 146). The experiment consisted of two stages, between which the ethnic status of the role models (majority vs minority) in stories read during the intervention sessions was changed. This was done to explore the impact of the in- and outgroup role models after the first stage, and to test the overall effect of the intervention on out-group attitudes and perceived in- and outgroup norms after participants were presented with both majority and minority storytellers after the second stage. The intervention affected the perceived outgroup norms among the minority participants as they perceived norms prevailing in the majority group to be more positive after the intervention. However, the ethnic status of the role models made no difference for any outcome variable. Ways to implement scientific knowledge into practice by providing research-based tools for multicultural education are discussed.
  • Jaatinen, Kim; Moller, Anders P.; Ost, Markus (2019)
    The direction of predator-mediated selection on brain size is debated. However, the speed and the accuracy of performing a task cannot be simultaneously maximized. Large-brained individuals may be predisposed to accurate but slow decision-making, beneficial under high predation risk, but costly under low risk. This creates the possibility of temporally fluctuating selection on brain size depending on overall predation risk. We test this idea in nesting wild eider females (Somateria mollissima), in which head volume is tightly linked to brain mass (r(2) = 0.73). We determined how female relative head volume relates to survival, and characterized the seasonal timing of predation. Previous work suggests that relatively large-brained and small-brained females make slow versus fast nest-site decisions, respectively, and that predation events occur seasonally earlier when predation is severe. Large-brained, late-breeding females may therefore have higher survival during high-predation years, but lower survival during safe years, assuming that predation disproportionately affects late breeders in such years. Relatively large-headed females outsurvived smaller-headed females during dangerous years, whereas the opposite was true in safer years. Predation events occurred relatively later during safe years. Fluctuations in the direction of survival selection on relative brain size may therefore arise due to brain-size dependent breeding phenology.
  • Roslund, Marja; Puhakka, Riikka; Grönroos, Mira; Nurminen, Noora; Oikarinen, Sami; Gazali, Ahmad M.; Cinek, Ondrej; Kramna, Lenka; Siter, Nathan; Vari, Heli; Soininen, Laura; Parajuli, Anirudra; Rajaniemi, Juho; Kinnunen, Tuure; Laitinen, Olli H.; Hyöty, Heikki; Sinkkonen, Aki; The ADELE Research Group (2020)
    As the incidence of immune-mediated diseases has increased rapidly in developed societies, there is an unmet need for novel prophylactic practices to fight against these maladies. This study is the first human intervention trial in which urban environmental biodiversity was manipulated to examine its effects on the commensal microbiome and immunoregulation in children. We analyzed changes in the skin and gut microbiota and blood immune markers of children during a 28-day biodiversity intervention. Children in standard urban and nature-oriented daycare centers were analyzed for comparison. The intervention diversified both the environmental and skin Gammaproteobacterial communities, which, in turn, were associated with increases in plasma TGF-beta 1 levels and the proportion of regulatory T cells. The plasma IL-10:IL-17A ratio increased among intervention children during the trial. Our findings suggest that biodiversity intervention enhances immunoregulatory pathways and provide an incentive for future prophylactic approaches to reduce the risk of immune-mediated diseases in urban societies.
  • Meysick, Lukas; Ysebaert, Tom; Jansson, Anna; Montserrat, Fransesc; Valanko, Sebastian; Villnäs, Anna; Boström, Christoffer; Norkko, Joanna; Norkko, Alf (2019)
    Foundation species host diverse associated communities by ameliorating environmental stress. The strength of this facilitative effect can be highly dependent on the underlying biotic and abiotic context. We investigated community level patterns of macrofauna associated with and adjacent to the marine foundation species eelgrass (Zostera marina) along a hydrodynamic stress gradient. We could demonstrate that the relative importance of this foundation species for its infaunal community increases with environmental variables associated with increasing hydrodynamic stress (depth, sand ripples formation, sediment grain size and organic content). Faunal assemblages in proximity to the Zostera patch edges, however, showed no (infauna) or negative (epifauna) response to hydrodynamic stress. Our study highlights that the facilitative outcome of a foundation species is conditional to the faunal assemblage in question and can be highly variable even between positions within the habitat.
  • Chen, Jing; Bacelis, Jonas; Sole-Navais, Pol; Srivastava, Amit; Juodakis, Julius; Rouse, Amy; Hallman, Mikko; Teramo, Kari; Melbye, Mads; Feenstra, Bjarke; Freathy, Rachel M.; Smith, George Davey; Lawlor, Deborah A.; Murray, Jeffrey C.; Williams, Scott M.; Jacobsson, Bo; Muglia, Louis J.; Zhang, Ge (2020)
    Author summaryWhy was this study done? Maternal height, BMI, blood glucose, and blood pressure are associated with gestational duration, birth weight, and birth length. These birth outcomes are subsequently associated with late-onset health conditions. The causal mechanisms and the relative contributions of maternal and fetal genetic effects underlying these observed associations are not clear. What did the researchers do and find? We dissected the relative contributions of maternal and fetal genetic effects using haplotype genetic score analysis in 10,734 mother-infant pairs of European ancestry. Genetically elevated maternal height is associated with longer gestational duration and larger birth size. In the fetus, alleles associated with adult height are positively associated with birth size. Alleles elevating blood pressure are associated with shorter gestational duration through a maternal effect and are associated with reduced fetal growth through a fetal genetic effect. Alleles that increase blood glucose in the mother are associated with increased birth weight, whereas risk alleles for type 2 diabetes in the fetus are associated with reduced birth weight. Alleles raising birth weight in fetus are associated with shorter gestational duration and higher maternal blood pressure during pregnancy. What do these findings mean? Maternal size and fetal growth are important factors in shaping the duration of gestation. Fetal growth is influenced by both maternal and fetal effects. Higher maternal BMI and glucose levels positively associate with birth weight through maternal effects. In the fetus, alleles associated with higher metabolic risks are negatively associated with birth weight. More rapid fetal growth is associated with shorter gestational duration and higher maternal blood pressure. These maternal and fetal genetic effects can largely explain the observed associations between maternal phenotypes and birth outcomes, as well as the life-course associations between these birth outcomes and adult phenotypes. Background Many maternal traits are associated with a neonate's gestational duration, birth weight, and birth length. These birth outcomes are subsequently associated with late-onset health conditions. The causal mechanisms and the relative contributions of maternal and fetal genetic effects behind these observed associations are unresolved. Methods and findings Based on 10,734 mother-infant duos of European ancestry from the UK, Northern Europe, Australia, and North America, we constructed haplotype genetic scores using single-nucleotide polymorphisms (SNPs) known to be associated with adult height, body mass index (BMI), blood pressure (BP), fasting plasma glucose (FPG), and type 2 diabetes (T2D). Using these scores as genetic instruments, we estimated the maternal and fetal genetic effects underlying the observed associations between maternal phenotypes and pregnancy outcomes. We also used infant-specific birth weight genetic scores as instrument and examined the effects of fetal growth on pregnancy outcomes, maternal BP, and glucose levels during pregnancy. The maternal nontransmitted haplotype score for height was significantly associated with gestational duration (p= 2.2 x 10(-4)). Both maternal and paternal transmitted height haplotype scores were highly significantly associated with birth weight and length (p<1 x 10(-17)). The maternal transmitted BMI scores were associated with birth weight with a significant maternal effect (p= 1.6 x 10(-4)). Both maternal and paternal transmitted BP scores were negatively associated with birth weight with a significant fetal effect (p= 9.4 x 10(-3)), whereas BP alleles were significantly associated with gestational duration and preterm birth through maternal effects (p= 3.3 x 10(-2)andp= 4.5 x 10(-3), respectively). The nontransmitted haplotype score for FPG was strongly associated with birth weight (p= 4.7 x 10(-6)); however, the glucose-increasing alleles in the fetus were associated with reduced birth weight through a fetal effect (p= 2.2 x 10(-3)). The haplotype scores for T2D were associated with birth weight in a similar way but with a weaker maternal effect (p= 6.4 x 10(-3)) and a stronger fetal effect (p= 1.3 x 10(-5)). The paternal transmitted birth weight score was significantly associated with reduced gestational duration (p= 1.8 x 10(-4)) and increased maternal systolic BP during pregnancy (p= 2.2 x 10(-2)). The major limitations of the study include missing and heterogenous phenotype data in some data sets and different instrumental strength of genetic scores for different phenotypic traits. Conclusions We found that both maternal height and fetal growth are important factors in shaping the duration of gestation: genetically elevated maternal height is associated with longer gestational duration, whereas alleles that increase fetal growth are associated with shorter gestational duration. Fetal growth is influenced by both maternal and fetal effects and can reciprocally influence maternal phenotypes: taller maternal stature, higher maternal BMI, and higher maternal blood glucose are associated with larger birth size through maternal effects; in the fetus, the height- and metabolic-risk-increasing alleles are associated with increased and decreased birth size, respectively; alleles raising birth weight in the fetus are associated with shorter gestational duration and higher maternal BP. These maternal and fetal genetic effects may explain the observed associations between the studied maternal phenotypes and birth outcomes, as well as the life-course associations between these birth outcomes and adult phenotypes.
  • Vesala, Risto; Niskanen, Tuula; Liimatainen, Kare; Boga, Hamadi; Pellikka, Petri; Rikkinen, Jouko (2017)
    Fungus-growing termites of the subfamily Macrotermitinae together with their highly specialized fungal symbionts (Termitomyces) are primary decomposers of dead plant matter in many African savanna ecosystems. The termites provide crucial ecosystem services also by modifying soil properties, translocating nutrients, and as important drivers of plant succession. Despite their obvious ecological importance, many basic features in the biology of fungus-growing termites and especially their fungal symbionts remain poorly known, and no studies have so far focused on possible habitat-level differences in symbiont diversity across heterogeneous landscapes. We studied the species identities of Macrotermes termites and their Termitomyces symbionts by excavating 143 termite mounds at eight study sites in the semiarid Tsavo Ecosystem of southern Kenya. Reference specimens were identified by sequencing the COI region from termites and the ITS region from symbiotic fungi. The results demonstrate that the regional Macrotermes community in Tsavo includes two sympatric species (M. subhyalinus and M. michaelseni) which cultivate and largely share three species of Termitomyces symbionts. A single species of fungus is always found in each termite mound, but even closely adjacent colonies of the same termite species often house evolutionarily divergent fungi. The species identities of both partners vary markedly between sites, suggesting hitherto unknown differences in their ecological requirements. It is apparent that both habitat heterogeneity and disturbance history can influence the regional distribution patterns of both partners in symbiosis.
  • Chiner-Oms, Á.; Sánchez-Busó, L.; Corander, J.; Gagneux, S.; Harris, S. R.; Young, D.; González-Candelas, F.; Comas, I. (2019)
    Models on how bacterial lineages differentiate increase our understanding of early bacterial speciation events and the genetic loci involved. Here, we analyze the population genomics events leading to the emergence of the tuberculosis pathogen. The emergence is characterized by a combination of recombination events involving core pathogenesis functions and purifying selection on early diverging loci. We identify the phoR gene, the sensor kinase of a two-component system involved in virulence, as a key functional player subject to pervasive positive selection after the divergence of the Mycobacterium tuberculosis complex from its ancestor. Previous evidence showed that phoR mutations played a central role in the adaptation of the pathogen to different host species. Now, we show that phoR mutations have been under selection during the early spread of human tuberculosis, during later expansions, and in ongoing transmission events. Our results show that linking pathogen evolution across evolutionary and epidemiological time scales points to past and present virulence determinants.
  • Marcinkowska, Urszula M.; Terraube, Julien; Kaminski, Gwenael (2016)
    Faces are an important cue to multiple physiological and psychological traits. Human preferences for exaggerated sex typicality (masculinity or femininity) in faces depend on multiple factors and show high inter-subject variability. To gain a deeper understanding of the mechanisms underlying facial femininity preferences in men, we tested the interactive effect of family structure (birth order, sibling sex-ratio and number of siblings) and parenthood status on these preferences. Based on a group of 1304 heterosexual men, we have found that preference for feminine faces was not only influenced by sibling age and sex, but also that fatherhood modulated this preference. Men with sisters had a weaker preference for femininity than men with brothers, highlighting a possible effect of a negative imprinting-like mechanism. What is more, fatherhood increased strongly the preference for facial femininity. Finally, for fathers with younger sisters only, the more the age difference increased between them, the more femininity preference increased. Overall our findings bring new insight into how early-acquired experience at the individual level may determine face preference in adulthood, and what is more, how these preferences are flexible and potentially dependent on parenthood status in adult men.
  • Kuusimäki, Tomi; Al-Abdulrasul, Haidar; Kurki, Samu; Hietala, Jarmo; Hartikainen, Sirpa; Koponen, Marjaana; Tolppanen, Anna-Maija; Kaasinen, Valtteri (2021)
    Background PD comorbid with schizophrenia has been considered rare because these diseases associate with opposite alterations in the brain dopamine system. The objective of this study was to investigate the risk of PD after a diagnosis of a schizophrenia spectrum disorder. Methods Regionally, this was a retrospective record-based case-control study. The cohort included 3045 PD patients treated 2004-2019 in southwestern Finland. Nationally this was a nested case-control study using registers to examine Finnish patients who received a clinically confirmed PD diagnosis 1996-2015 (n = 22,189). PD patients with previously diagnosed schizophrenia spectrum disorder (separate analysis for schizophrenia) were included. Comparable non-PD control groups were derived from both data sets. All PD diagnoses were based on individual clinical examinations by certified neurologists. Results In PD patients, the prevalence of earlier schizophrenia spectrum disorder was 0.76% in regional data and 1.50% in nationwide data. In age-matched controls, the prevalence in the regional and national data was 0.16% and 1.31%, respectively. The odds ratio for PD after schizophrenia spectrum disorder diagnosis was 4.63 (95% CI, 1.76-12.19; P <0.01) in the regional data and 1.17 (95% CI, 1.04-1.31; P <0.01) in the national data. Conclusions Schizophrenia spectrum disorder increases the risk of PD later in life. This association was observed in both individual patient data and nationwide register data. Therefore, despite the opposite dopaminergic disease mechanisms, schizophrenia spectrum disorder increases rather than decreases the risk of PD. The increased PD risk could be related to risk-altering effects of dopamine receptor antagonists or to the increased vulnerability of the dopamine system induced by illness phase-dependent dopamine dysregulation in schizophrenia/schizophrenia spectrum disorder. (c) 2021 International Parkinson and Movement Disorder Society
  • Kruskopf, Milla; Hakkarainen, Kai; Li, Shupin; Lonka, Kirsti (2021)
    The rise of modern socio-digital technologies has fundamentally changed the everyday environments in which young people communicate with each other and cultivate interests. To gain a more sophisticated understanding of this phenomenon, this study provides in-depth, qualitative insights into adolescents’ experiences of their socio-digital developmental ecologies. The 15 interview participants were recruited based on a previously conducted questionnaire. The semi-structured theme interview addressed the socio-digital aspects of the participants’ interest-driven behaviours and related networks with the aid of participant-generated egocentric maps. The data not only qualitatively enrich the picture on adolescents’ friendship- and interest-driven socio-digital participation but also provide new perspectives on the phenomena through the added network-layer of analysis. The youth seem to vary in their motivational profiles related to their participation and the potential relevant psychological background factors for this variation are considered. Educational implications of these results are discussed when it comes to effective student engagement and connected learning.
  • Di Battista, Silvia; Pivetti, Monica; Vainio, Annukka; Berti, Chiara (2020)
    Sacred values are moral foundations that may make public and political debates among groups hard to resolve. A taboo trade-off framework offers the opportunity of measuring the inviolability and the "sacralization" of moral foundations. In this study, moral foundations in a taboo trade-off framework were assessed in a convenience sample of Italians (N = 224) using a new measure to assess sacred values, the Omission as a Compromise on Moral Foundations scale (OC-MF). The OC-MF measures the willingness of individuals to omit moral foundations in exchange for money. It was predicted that Italian center and left-wing participants would be less willing to compromise individualizing moral foundations as opposed to binding ones, and that center and right-wing participants would be less willing to compromise on binding moral foundations than left-wing participants. Confirmatory Factor Analyses demonstrated the two-factor structure of the OC-MF: individualizing and binding. As predicted, Repeated Measures Anova showed that political orientation was related with differential adoptions of moral foundations as sacred values, with center and left-wing participants refusing to compromise more on individualizing than on binding moral foundations. Moreover, left-wing participants were more willing to compromise on binding moral foundations than center and right-wing participants. The OC-MF shows the hypothesized differences between Italian political groups and offers a new understanding of moral reasoning. These findings provide opportunities for improving ideological debates concerning sacred values.
  • Lavikainen, Antti; Iwaki, Takashi; Haukisalmi, Voitto; Konyaev, Sergey V.; Casiraghi, Maurizio; Dokuchaev, Nikolai E.; Galimberti, Andrea; Halajian, Ali; Henttonen, Heikki; Ichikawa-Seki, Madoka; Itagaki, Tadashi; Krivopalov, Anton V.; Meri, Seppo; Morand, Serge; Nareaho, Anu; Olsson, Gert E.; Ribas, Alexis; Terefe, Yitagele; Nakao, Minoru (2016)
    The common cat tapeworm Hydatigera taeniaeformis is a complex of three morphologically cryptic entities, which can be differentiated genetically. To clarify the biogeography and the host spectrum of the cryptic lineages, 150 specimens of H. taeniaeformis in various definitive and intermediate hosts from Eurasia, Africa and Australia were identified with DNA barcoding using partial mitochondrial cytochrome c oxidase subunit 1 gene sequences and compared with previously published data. Additional phylogenetic analyses of selected isolates were performed using nuclear DNA and mitochondrial genome sequences. Based on molecular data and morphological analysis, Hydatigera kamiyai n. sp. Iwaki is proposed for a cryptic lineage, which is predominantly northern Eurasian and uses mainly arvicoline rodents (voles) and mice of the genus Apodemus as intermediate hosts. Hydatigera taeniaeformis sensu stricto (s.s.) is restricted to murine rodents (rats and mice) as intermediate hosts. It probably originates from Asia but has spread worldwide. Despite remarkable genetic divergence between H. taeniaeformis s.s. and H. kamiyai, interspecific morphological differences are evident only in dimensions of rostellar hooks. The third cryptic lineage is closely related to H. kamiyai, but its taxonomic status remains unresolved due to limited morphological, molecular, biogeographical and ecological data. This Hydatigera sp. is confined to the Mediterranean and its intermediate hosts are unknown. Further studies are needed to classify Hydatigera sp. either as a distinct species or a variant of H. kamiyai. According to previously published limited data, all three entities occur in the Americas, probably due to human-mediated introductions. (C) 2016 Australian Society for Parasitology Inc. Published by Elsevier Ltd. All rights reserved.
  • Vesala, Risto; Harjuntausta, Anni; Hakkarainen, Anu; Rönnholm, Petri; Pellikka, Petri; Rikkinen, Jouko (2019)
    Background Large and complex mounds built by termites of the genus Macrotermes characterize many dry African landscapes, including the savannas, bushlands, and dry forests of the Tsavo Ecosystem in southern Kenya. The termites live in obligate symbiosis with filamentous fungi of the genus Termitomyces. The insects collect dead plant material from their environment and deposit it into their nests where indigestible cell wall compounds are effectively decomposed by the fungus. Above-ground mounds are built to enhance nest ventilation and to maintain nest interior microclimates favorable for fungal growth. Objectives In Tsavo Ecosystem two Macrotermes species associate with three different Termitomyces symbionts, always with a monoculture of one fungal species within each termite nest. As mound architecture differs considerably both between and within termite species we explored potential relationships between nest thermoregulatory strategies and species identity of fungal symbionts. Methods External dimensions were measured from 164 Macrotermes mounds and the cultivated Termitomyces species were identified by sequencing internal transcribed spacer (ITS) region of ribosomal DNA. We also recorded the annual temperature regimes of several termite mounds to determine relations between mound architecture and nest temperatures during different seasons. Results Mound architecture had a major effect on nest temperatures. Relatively cool temperatures were always recorded from large mounds with open ventilation systems, while the internal temperatures of mounds with closed ventilation systems and small mounds with open ventilation systems were consistently higher. The distribution of the three fungal symbionts in different mounds was not random, with one fungal species confined to “hot nests.” Conclusions Our results indicate that different Termitomyces species have different temperature requirements, and that one of the cultivated species is relatively intolerant of low temperatures. The dominant Macrotermes species in our study area can clearly modify its mound architecture to meet the thermal requirements of several different symbionts. However, a treacherous balance seems to exist between symbiont identity and mound architecture, as the maintenance of the thermophilic fungal species obviously requires reduced mound architecture that, in turn, leads to inadequate gas exchange. Hence, our study concludes that while the limited ventilation capacity of small mounds sets strict limits to insect colony growth, in this case, improving nest ventilation would invariable lead to excessively low nest temperatures, with negative consequences to the symbiotic fungus.